Improve setup of GitHub webhook and integration after setting up pull mirroring
What
System to configure GitHub webhook while setting up mirroring, as well as enabling the GitHub integration.
This could be via checkbox on that page when enabling mirroring. We could make the checkbox visible when the URL contains github
somewhere in it. This should catch most cases as GitHub.com will be caught as well as any GitHub Enterprise installations on a github
subdomain.
We might also want to consider allowing the webhook to be set up when activating the GitHub integration. Maybe if we did this we'd only have a link from the mirroring page, ensuring that the webhook could always be set up.
Why
Allow GitHub webhook to be set up outside of the import flow. Make it easier to discover the GitHub integration when setting up mirroring instead of expecting users to know about it and then navigate to the integrations page.
The webhook will then trigger mirroring after a change on GitHub and the integration will send CI/CD status updates back to GitHub.
Especially useful when using GitHub Enterprise with GitLab.com, since mirroring has to be manually set up in that flow